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Fang-Yue Lin

Publications and source records attributed to Fang-Yue Lin.

48 records · Page 3Linked to original sources
PubMed2003

Atrial compartment operation for atrial fibrillation: to isolate the left atrium or not?

BACKGROUND: The atrial compartment operation was designed to convert atrial fibrillation (AF) to sinus rhythm with intentional preservation of the electrical connection between adjacent atrial compartments. However, incidental left atrial isolation was observed in some patients. This study compared the long-term clinical outcomes of left atrial isolation for AF with those with right and left atrial connection. METHODS: Twenty patients with mitral valve disease and chronic AF who underwent atrial compartment operation with successful sinus conversion were studied. Left atrial isolation was documented by local electrogram recording. When there were no signs of electrical connection between the left atrium and the rest of the heart, either during sinus rhythm or during stimulation from various atrial compartments, left atrial isolation was confirmed. All patients were followed by electrocardiogram and echocardiogram serial recordings. Clinical signs and symptoms of cardiac performance and thromboembolism were also examined. RESULTS: Seven patients showed an isolated left atrium and 13 patients had electrical connection between the right and left atria. The age, gender, AF duration, and underlying disease were not different between the two groups of patients. During a mean follow-up period of 66 +/- 15 months, none of the patients with left atrial isolation showed recurrence of AF, although one experienced paroxysmal atrial flutter. However, 8 of the 13 patients with right and left atrial connection experienced recurrent atrial flutter/fibrillation (6 atrial flutter and 5 AF) (p = 0.058). The propensity for recurrent atrial flutter/fibrillation in these patients may be related to the conduction delay between the two atrial compartments, measured at 142 +/- 48 ms. At the end of the follow-up period, all patients with left atrial isolation remained in normal sinus rhythm without antiarrhythmic drugs. Of the patients who had right and left atrial connection, 2 developed sustained AF and 1 developed atrial flutter. Patients with left atrial isolation showed a decreased transmitral "A" flow compared with those with right and left atrial connection. Postoperative left atrial diameter and clinical functional class did not differ between patients with and without left atrial isolation. The incidence of embolization observed in both treatment groups did not differ significantly: 14% (1/7) in patients with left atrial isolation and 8% (1/13) in patients with right and left atrial connection (p > 0.05 between the groups). CONCLUSIONS: Left atrial isolation confers a better arrhythmia outcome but at the expense of poorer mechanical performance as compared with preserved electrical connection between the two atria. Nonetheless, all patients remain at risk for systemic embolization. Therefore, modifications of current surgical incisions for AF are needed.

Adult↗
PubMed2003

Long-term evaluation of Carpentier-Edwards porcine bioprosthesis for rheumatic heart disease.

OBJECTIVES: The clinical results of Carpentier-Edwards standard bioprosthesis have been extensively studied for valvular heart surgery in America and Europe. However, the data of long-term performance of Carpentier-Edwards standard porcine valve in areas with a high prevalence of rheumatic heart disease are still lacking. In this study, we assessed the clinical performance of Carpentier-Edwards standard porcine bioprostheses in a patient group with high prevalence of rheumatic heart disease. METHODS: A total of 872 patients underwent valvular heart surgery with Carpentier-Edwards standard porcine bioprostheses replacement between 1975 and 1999 and the results were analyzed. Rheumatic etiology counts for 95% of the patients. Mean age of operation was 40 +/- 14 years (mitral valve), 43 +/- 19 years (aortic valve), and 45 +/- 13 years (double valve). Follow-up was 95.6% complete and continued up to 24 years (total 7017 patient-years) with mean of 8.9 +/- 5.1 years. RESULTS: The operative mortality rate was 5.85%. Actuarial patient survival rates after discharge at 5, 10, 15, and 20 years were 92.5%, 83.8%, 72.3%, and 35.8%, respectively. A total of 442 cases received reoperation due to failure of bioprostheses. The mean duration to valve failure is 12.2 +/- 0.4 years. Actuarial estimate of freedom from structural valvular failure at 5, 10, 15, and 20 years were 96.3%, 63.7%, 24.4%, and 7.7%, respectively. CONCLUSION: The long-term result of Carpentier-Edwards standard bioprostheses in the present patient group is satisfactory. However, freedom from valve failure is lower than that of Western series. Younger age at operation and higher prevalence of rheumatic etiology in this area are possible causes.

Adolescent↗
PubMed2003

Characteristic P wave morphology in patients undergoing the atrial compartment operation for chronic atrial fibrillation with mitral valve disease.

The P wave in the surface ECG represents atrial electrical activation and may be altered in certain pathological conditions. Atrial compartment operation has been used to convert chronic AF to sinus rhythm. However, this procedure may result in changes of impulse conduction in various atrial compartments and alters the P wave morphology. This study sought to elucidate the P wave changes after the atrial compartment operation for AF. Fifteen patients undergoing the atrial compartment operation for chronic AF were studied. In the operation, the atrium was divided into three compartments, namely the left atrium, the atrial septum including sinus and AV nodes, and the right atrial compartment. The anatomic connection between adjacent compartments were preserved at the posterior lower margin of incisions. The surface lead P waves were correlated with intracardiac recording and stimulation in various atrial compartments. Fifteen age- and sex-matched control patients without structural heart diseases were compared. The results showed that patients undergoing the atrial compartment operation had a prolonged P wave duration (190 +/- 27 v s95 +/- 14 ms, P < 0.001), a prolonged PR interval (207 +/- 23 vs 155 +/- 20 ms, P < 0.001), and a shortened PR segment (17 +/- 19 vs 60 +/- 17 ms, P < 0.001). The increase in P wave duration was primarily due to a conduction delay from the sinus node to the other atrial compartments as the conduction time from the high right atrium to the right atrial appendage was 132 +/- 57 ms(vs 21 +/- 6 ms for control,P < 0.001), and the conduction time from the high right atrium to the distal coronary sinus was 140 +/- 55 ms(vs 70 +/- 15 ms, P < 0.001). However, the conduction from the high right atrium to the low septal right atrium, which were located in the same compartment, was not impaired. Also, the conduction in the AV node and His-Purkinje system were not impaired. The mean axis of P waves varied greatly, but was not statistically different from that of the control group (60 +/- 48 degrees vs 52 +/- 18 degrees,P > 0.05). Although the patients undergoing atrial compartment operation had a larger left atrial size, their P wave amplitude was smaller (1.0 +/- 0.3 vs 1.3 +/- 0.3 mm, P < 0.01), and an increased negative terminal force in V1 was not seen (0.02 +/- 0.02 vs 0.02 +/- 0.01 mm/s, P > 0.05). Alteration in P wave morphology was seen in 14 patients. All the P waves showed a biphasic configuration with an initial positive and a terminal slurred negative deflection in leads II, III, and aVF. The terminal components represented the activation of right atrial appendage in 5 patients, the left atrium in 1, and the combined activation of right atrial appendage and the left atrium in 8 patients. The P wave morphology suggested that activation of both the right atrial appendage and the left atrial compartments proceeded in a caudocranial direction as a result of the atrial incisions. In conclusion, atrial compartment operation altered the conduction time and direction in the atria and resulted in characteristic P wave changes.

Adult↗
PubMed2003

Comparison of outcome of off-pump coronary artery bypass surgery and conventional coronary artery bypass surgery.

BACKGROUND AND PURPOSE: Off-pump coronary artery bypass grafting (CABG) [OPCAB] is preferred to conventional CABG with cardiopulmonary bypass (CPB) for many specific subgroups, such as elderly patients and high-risk patients. Whether OPCAB should be the first choice of surgical procedure for a wider range of coronary artery disease patient subgroups remains controversial. The purpose of this study was to compare the clinical results of OPCAB and CPB in our hospital. METHODS: We retrospectively analyzed the results for 404 patients who received OPCAB or CPB between March 2000 and December 2001. Surgical methods adopted were at the discretion of the attending surgeon. In addition, subgroups of patients were analyzed to assess whether or not OPCAB was more successful in patients with specific characteristics. RESULTS: There were no significant differences in the demographic data between the 2 groups. The perioperative mortality rate was similar for the CPB and OPCAB groups (2.5% and 2.0%, respectively; p = 1.00.) OPCAB was superior with respect to inotropic use, postoperative bleeding amount, transfusion amount, and length of intensive care unit and hospital stay (p < 0.05 for all), and also had a lower incidence of re-entry due to bleeding (6.7% vs 13.6%, p = 0.04) and prolonged hospitalization > 30 days (1.5% vs 10.8%, p < 0.01). At 12 months' follow-up, the OPCAB group had a lower rate of mortality (1.5% vs 5.6%, p = 0.03) and a comparable rate of readmission for cardiac reasons (6.6% vs 9.6%, p = 0.28). The rate of poor in-hospital outcome was lower in the OPCAB than in the CPB group (3.0% vs 13.3%, p </= 0.01), while the percentage with poor results on follow-up was comparable between the 2 groups (7.1% vs 12.1%, p = 0.09). In addition, subgroups defined as: female, age > 65 years, age < 65 years, diabetes, peripheral arterial occlusive disease, end-stage renal disease, left ventricular ejection fraction < 50%, preoperative intra-aortic balloon pump use, and left-main disease had better in-hospital outcome in the OPCAB group compared with the CPB group, while no subgroups had worse in-hospital outcomes with OPCAB. The 12-month follow-up outcome was similar with the 2 techniques. CONCLUSION: Use of OPCAB in CABG operation was associated with improved in-hospital outcome and similar follow-up outcome compared to CPB. No subgroup had a worse outcome with OPCAB.

Aged↗
PubMed2003

Implications of prolonged pause in patients with chronic atrial fibrillation with mitral valve disease undergoing atrial compartment operation.

BACKGROUND AND PURPOSE: Prolonged pause is commonly seen in patients with atrial fibrillation (AF), but the electrophysiologic mechanism and clinical importance of this phenomenon are not clear. This study examined the incidence and clinical importance of prolonged pause in patients with chronic AF and mitral valve disease before and after AF surgery. METHODS: Holter recordings were made in 53 mitral valve patients undergoing concomitant valve surgery and atrial compartment operation for chronic AF. There were 38 patients (72%) with successful AF conversion and 15 patients (28%) with failed AF conversion. Cardiac rhythms before and after operation were compared. An R-R interval > or = 2.0 sec was defined as prolonged pause. Serum digoxin and potassium concentration were determined within 24 hours of Holter monitoring. RESULTS: Before operation, prolonged ventricular pause was common during AF in both groups (76% for the successful AF conversion group and 73% for the failed AF conversion group, p > 0.05). There were 62 +/- 77 episodes of prolonged pause in the successful AF conversion group and 59 +/- 44 in the failed group (p > 0.05). The longest pause lasted 2.47 +/- 0.26 sec in the successful AF conversion group and 2.43 +/- 0.41 sec in the failed AF conversion group (p > 0.05), with most prolonged pauses occurring at night (72% in the successful and 73% in the failed AF conversion group, p > 0.05). After conversion to sinus rhythm, only 1 patient (3%) showed an episode of prolonged pause (p < 0.001). No patient exhibited atrioventricular (AV) block. In patients with successful AF conversion, the maximal heart rate decreased from 150 +/- 28 to 126 +/- 17 beats/min (p < 0.001), the minimal heart rate increased from 43 +/- 6 to 56 +/- 5 beats/min (p < 0.001), and ventricular premature beats (VPB) counts decreased from 599 +/- 935 to 223 +/- 453/24 hours (p < 0.05). In contrast, patients with failed AF conversion showed no significant changes in the incidence of prolonged pause, maximal and minimal heart rates, and VPB counts after operation. None of the patients received pacemaker implantation during a mean follow-up period of 42 +/- 11 months in the successful group and 45 +/- 13 months in the failed AF conversion group. CONCLUSION: We conclude that prolonged pause is common in AF with mitral valve disease and does not indicate the presence of sinus or AV nodal dysfunction requiring artificial pacing.

Atrial Fibrillation↗
PubMed2002

Extracorporeal membrane oxygenation support for adult postcardiotomy cardiogenic shock.

BACKGROUND: Postcardiotomy cardiogenic shock occasionally develops in patients who have undergone cardiac procedures. We report our experience using extracorporeal membrane oxygenation (ECMO) in adult patients with postcardiotomy cardiogenic shock, and analyze the factors that affected outcomes for these ECMO patients. METHODS: We retrospectively reviewed the medical records of ECMO patients. RESULTS: From August 1994 to May 2000, 76 adult patients (48 men, 28 women; mean age, 56.8+/-15.9 years) received ECMO support for postcardiotomy cardiogenic shock at the National Taiwan University Hospital. The mean ECMO blood flow was 2.53+/-0.84 L/min. The cardiac operations included coronary artery bypass grafting (n = 37), coronary artery bypass grafting and valvular operation (n = 6), valvular operation alone (n = 14), heart transplantation (n = 12), correction of congenital heart defects (n = 3), implantation of a left ventricular assist device (n = 2), and aortic operations (n = 2). Fifty-four patients received ECMO support after intraaortic balloon pumping, but 22 patients directly received ECMO support. Two patients were bridged to heart transplantation and two bridged to ventricular assist devices. Thirty patients died on ECMO support. The causes of mortality included brain death (n = 3), refractory arrhythmia (n = 2), near motionless heart (n = 2), acute graft rejection (n = 1), primary graft failure (n = 1), uncontrolled bleeding (n = 5), and multiple organ failure (n = 16). Twenty-two patients were weaned off ECMO support but presented intrahospital mortality. The cause of mortality included brain death (n = 1), sudden death (n = 4), and multiple organ failure (n = 17). Twenty patients were weaned off ECMO support and survived to hospital discharge. During the follow-up of 33+/-22 months, all were in New York Heart Association functional status I or II except two cases of late deaths. Among the ECMO-weaned patients, "dialysis for acute renal failure" was a significant factor in reducing the chance of survival. CONCLUSIONS: The ECMO provided a satisfactory partial cardiopulmonary support to patients with postcardiotomy cardiogenic shock, and allowed time for clinicians to assess the patients and make appropriate decisions.

Adult↗
PubMed2002

Selective use of ultrasonography for the detection of pneumoperitoneum.

OBJECTIVE: Whether ultrasonography is superior to plain radiography for the detection of pneumoperitoneum is unknown. The goal of this study was to determine the value of ultrasonography for the detection of pneumoperitoneum. METHODS: One hundred thirty-two patients with suspected hollow-organ perforation were prospectively selected for study. All 132 patients received ultrasonography, upright chest radiography, and left lateral decubitus abdominal radiography examinations. The diagnostic accuracies of chest and abdominal radiographs for the detection of pneumoperitoneum were compared with corresponding values from ultrasonography. RESULTS: Of the 125 patients who underwent laparotomy, 121 patients had hollow-organ perforation, three patients had perforated appendicitis, and one patient had acute cholecystitis. For the diagnosis of pneumoperitoneum, ultrasonography demonstrated a sensitivity of 93%, a specificity of 64%, a positive predictive value of 97%, a negative predictive value of 44%, and an accuracy of 90%. Plain radiography revealed a sensitivity of 79%, a specificity of 64%, a positive predictive value of 96%, a negative predictive value of 21%, and an accuracy of 77%. CONCLUSIONS: Ultrasonography is a more sensitive diagnosing modality than plain radiography for the diagnosis of pneumoperitoneum. The authors suggest that ultrasonography was a useful diagnostic modality when plain radiographs failed to reveal pneumoperitoneum among patients with suspected hollow-organ perforation.

Adolescent↗
PubMed2002

Successful rescue of sustained ventricular tachycardia/ventricular fibrillation after coronary artery bypass grafting by extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) can be set up quickly at the bedside and provides reliable temporary mechanical circulatory support for severe heart failure. We report the case of a 56-year-old female with circulatory collapse due to sustained ventricular tachycardia and ventricular fibrillation (VT/Vf) after coronary artery bypass grafting (CABG) who was successfully resuscitated using ECMO. The sustained VT/Vf might have been secondary to myocardial stunning, ischemia, infarction, or reperfusion. There were 40 cardioversions within the first 5 postoperative days. The patient improved after 8 days of ECMO in addition to use of an intraaortic balloon pump and administration of inotropic agents for profound heart failure. Left ventricular ejection fraction improved from 28% preoperatively to 54.5% on the 20th postoperative day. Cardiogenic shock due to sustained VT/Vf after CABG may be an indication for ECMO support. Immediate establishment of circulatory support using ECMO provides valuable time for spontaneous and interventional correction of reversible causes of sustained VT/Vf.

Coronary Artery Bypass↗
PubMedDate not supplied

Experience with extracorporeal life support in pediatric patients after cardiac surgery.

Extracorporeal life support (ECLS) had been successfully used in neonatal respiratory failure, but cardiac ECLS has been used increasingly in recent years. The purpose of this study was to review our experience in pediatric patients supported by ECLS for postoperative circulatory failure and to analyze the factors associated with mortality. Between January 1999 and December 2004, 68 pediatric patients (< 18 years old) who received ECLS within 7 days after cardiac surgery at the National Taiwan University Hospital were included in this study. The overall survival rate of this cohort was 32.4%. Age and gender did not affect survival. Patients with separate biventricular physiology had a higher probability of survival than those with systemic-pulmonary shunt or cavopulmonary anastomosis (41.3% vs. 13.6%, p < 0.05). Acute renal failure during ECLS was significantly associated with mortality (83% vs. 33.5%, p < 0.001). After ECLS initiation, the lowest lactate levels on the second to fourth days were lower in survivors than in nonsurvivors (2.4 vs. 3.3 mmol/L, p < 0.05). There was a trend toward a better survival in the most recent 2 years in comparison with the previous 4 years (47.6% vs. 25.5%, p = 0.07), although this trend did not reach statistical significance. In conclusion, nonbiventricular physiology, acute renal failure, and high blood lactate levels after ECLS increased the risk of mortality for pediatric patients requiring ECLS for postoperative cardiac support.

Acute Disease↗
PubMedDate not supplied

Extracorporeal membrane oxygenation for perioperative cardiac allograft failure.

The utility of mechanical support in pretransplant stabilization and postcardiotomy shock is well established, but its use in perioperative cardiac allograft failure (PCAGF) rescue has not been well documented. Ventricular assist devices (VADs) have been applied to PCAGF rescue with acceptable results. However, studies have not described the results of using extracorporeal membrane oxygenation (ECMO) in PCAGF. We evaluated the outcome of PCAGF rescue with ECMO. A retrospective review of 204 consecutive heart transplants revealed 19 cases of PCAGF requiring ECMO rescue. Donor-, surgery- and ECMO-related variables were evaluated for association with operative mortality, success of weaning, and survival rate. Transplant recipients included 14 males and 5 females with median age of 44.2 years. Weaning rate was 84.2% and survival rate was 52.6%, with duration of ECMO support 157 +/- 129 hours. Long ischemic time is a PCAGF risk factor (206.8 +/- 96.1 minutes vs. 158.3 +/- 60.8 minutes in non-PCAGF, p < 0.05). PCAGF etiology included primary graft failure (n = 7); right heart failure secondary to pulmonary hypertension, coagulopathy/intraoperative hemorrhage (n = 7); and sepsis (n = 2). Compared with data from VAD-supported PCAGF, ECMO had a better weaning and graft survival rates (p < 0.05). ECMO is another choice for PCAGF rescue. It has an acceptable survival rate and may be considered instead of VADs as a first-line rescue for PCAGF.

Adult↗